evdev: add evdev monitor for caps lock state

quickshell/Modules/OSD/CapsLockOSD.qml

@@ -0,0 +1,37 @@
+import QtQuick
+import qs.Common
+import qs.Services
+import qs.Widgets
+
+DankOSD {
+    id: root
+
+    osdWidth: Theme.iconSize + Theme.spacingS * 2
+    osdHeight: Theme.iconSize + Theme.spacingS * 2
+    autoHideInterval: 2000
+    enableMouseInteraction: false
+
+    property bool lastCapsLockState: false
+
+    Connections {
+        target: DMSService
+
+        function onCapsLockStateChanged() {
+            if (lastCapsLockState !== DMSService.capsLockState) {
+                root.show()
+            }
+            lastCapsLockState = DMSService.capsLockState
+        }
+    }
+
+    Component.onCompleted: {
+        lastCapsLockState = DMSService.capsLockState
+    }
+
+    content: DankIcon {
+        anchors.centerIn: parent
+        name: DMSService.capsLockState ? "shift_lock" : "shift_lock_off"
+        size: Theme.iconSize
+        color: Theme.primary
+    }
+}